docs: def _compute_mean(self, imt, mag, rhypo):
          """
          Compute mean value from lookup table.
  
          Lookup table defines log10(IMT) (in g) for combinations of Mw and
          log10(rhypo) values. ``mag`` is therefore converted from Mblg to Mw
          using Atkinson and Boore 1987 conversion equation. Mean value is
          finally converted from base 10 to base e.
          """
          mag = np.zeros_like(rhypo) + self._convert_magnitude(mag)
  
          # to avoid run time warning in case rhypo is zero set minimum distance
          # to 10, which is anyhow the minimum distance allowed by the tables
          rhypo[rhypo < 10] = 10
          rhypo = np.log10(rhypo)
  
          # create lookup table and interpolate it at magnitude/distance values
          table = RectBivariateSpline(
              self.MAGS, self.DISTS, self.IMTS_TABLES[imt].T
          )
          mean = table.ev(mag, rhypo)
  
          # convert mean from base 10 to base e
          return mean * np.log(10)